local Color = {}
Color.__index = Color

function Color.new(hex)
  local self = setmetatable({}, Color)
  hex = hex:gsub("^#", "")
  self.r = tonumber(hex:sub(1, 2), 16)
  self.g = tonumber(hex:sub(3, 4), 16)
  self.b = tonumber(hex:sub(5, 6), 16)
  return self
end

function Color:to_css()
  return string.format("#%02x%02x%02x", self.r, self.g, self.b)
end

function Color:blend(other, factor)
  other = type(other) == "string" and Color.new(other) or other
  return Color.new(
    string.format(
      "#%02x%02x%02x",
      math.floor(self.r + (other.r - self.r) * factor + 0.5),
      math.floor(self.g + (other.g - self.g) * factor + 0.5),
      math.floor(self.b + (other.b - self.b) * factor + 0.5)
    )
  )
end

function Color:darken(amount)
  return self:blend("#000000", amount)
end

function Color:lighten(amount)
  return self:blend("#ffffff", amount)
end

function Color:saturate(factor)
  local gray = math.floor(0.299 * self.r + 0.587 * self.g + 0.114 * self.b + 0.5)
  local gray_color = Color.new(string.format("#%02x%02x%02x", gray, gray, gray))
  return self:blend(gray_color, 1 - factor)
end

return setmetatable(Color, {
  __call = function(_, hex)
    return Color.new(hex)
  end,
})